title: Isolation, chemical and biological characterization of margaratensin, a neurotensin-related peptide from the skin of Rana margaratae.
abstract: A new neurotensin (NT)-related peptide, margaratensin, was obtained by Sep-Pak C18 and RP-HPLC from methanol extracts of the skin of Chinese frog Rana margaratae. The structure of the peptide has been determined to be Asp-Lys-Arg-Pro-Tyr-Ile-Leu-His-Glu, which is found to be homologous to the COOH-terminal sequence of NT, but has an extra His-Glu at the COOH-terminus. The synthetic preparation was shown to be indistinguishable from the native peptide during HPLC, amino acid analysis and bioassay. Margaratensin exhibited a hypotensive effect in the rat but the response was weaker than NT. The peptide could induce a potent and reproducible contractile activity on GPI which was different from xenopsin, another NT-related peptide from amphibian skin.
authors.affiliation: Shanghai Institute of Materia Medica, Academia Sinica, PRC.
authors.forename: Y Q
authors.initials: YQ
authors.lastname: Tang
authors.forename: S H
authors.initials: SH
authors.lastname: Tian
authors.forename: J C
authors.initials: JC
authors.lastname: Hua
authors.forename: S X
authors.initials: SX
authors.lastname: Wu
authors.forename: G
authors.initials: G
authors.lastname: Zou
authors.forename: K
authors.initials: K
authors.lastname: Tsou
authors.forename: G F
authors.initials: GF
authors.lastname: Wu
authors.forename: E M
authors.initials: EM
authors.lastname: Zhao
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000959:Antihypertensive Agents; D001794:Blood Pressure / Q000187:drug effects; D006168:Guinea Pigs; D008969:Molecular Sequence Data; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D011898:Ranidae; D051381:Rats; D012867:Skin / Q000737:chemistry*; D013329:Structure-Activity Relationship
chemical_list: D000959:Antihypertensive Agents; D010455:Peptides; C067265:magaratensin